Issue link: https://resources.mouser.com/i/1516386
What challenges do engineers face when selecting contactors? When selecting a contactor, engineers face numerous challenges: • Circuit conditions. Circuit contactors in EVs need to provide voltage isolation in the thousands-of-volts range and safely handle hundreds of amps. They also need to switch at a fast enough speed to limit voltage arcing. • Mechanical lifetime. A contactor should have a mechanical lifecycle greater than the life expectancy of the vehicle, even though it will undergo thousands of cycles. • Certification. Selected contactors need to be certified for use in vehicular applications, which experience unique vibrations, temperature swings, and lifecycles. • Circuit protection. Pairing contactors with the right fuses and transient voltage protection prevents damage to internal contacts, performance failures, and safety issues. Where will contactor technology go in the future? The push toward EVs has seen numerous high-voltage automotive contactor solutions become available on the market, helping engineers create evermore powerful control systems. Currently, inert gasses are used inside of contactors to reduce arcing, but these gases can also reduce contactor lifespan. Therefore, some contactor manufacturers seek to eliminate these gases to increase the lifespan—and reliability—of such contactors. Another area of interest is solid-state contactors. These switching devices have no moving parts and are entirely dependent on high-voltage semiconductors. C h a p t e r 4 | H i g h - V o l t a g e C o n t a c t o r s Most of the current contactors use an inert gas fill to help limit the arcing that takes place with high-voltage switching. So, eliminating the need for the gas fill will enable the contactor to have a longer life and match the life of the vehicle." Geoffrey Schwartz Business Development Manager, Technical Marketing Manager, Littelfuse 21 7 Experts on Automotive Powertrains